Acta naturalia Islandica - 01.02.1946, Blaðsíða 14

8
TRAUSTI EINARSSON
a proof of the Quaternary age of the Hreppar rocks. This appar-
ent inconsistency does, however, not appear in the final formu-
lation of Pjeturss’ views in 1910, where every moraine is considered
of Quaternary age.7) In 1905, however, Pjeturss thought it obvious
that the Fnjóskadalur moraines are older than the Pliocene of Tjör-
nes and it does not appear that it has been shown directly that the
relation is the reverse.
L. Hawkes thinks it quite obvious that the Fnjóskadalur sediments
are older than the Pliocene of Tjörnes.8) But Hawkes denies the exis-
tence of moraines at Fnjóskadalur where reported by Pjeturss. On
the other hand J. Líndal reports that he has found a number of
moraines in the mountains in question.9)
The existence of moraines in these localities seems thus to be
somewhat doubtful. But what about the age of these sediments? If
they are older than the Pliocene of Tjörnes and are genuine mora-
ines, then Pjeturss’ time-scale is entirely upset and we have got a
Tertiary glaciation of Iceland.
But Pjeturss system as a whole appears to be so well-founded that
it cannot be upset by this. The obvious answer to the difficulty just
mentioned would be that the moraines at Fnjóskadalur, if genuine,
must be younger than the Pliocene of Tjörnes. Some geologists,
however, believe that the Pliocene is younger than the “moraines”
and this is therefore still an open question. But it seems a priori
improbable that the answer to it can seriously influence Pjeturss’
system as a whole.
An apparent weakness of the system, which L. Hawkes has already
pointed out is the tremendous work of modelling the fjord land-
scape of Northern and Western Iceland which according to the
system was carried out during part of the Quaternary period. But
this is perhaps no real weakness. According to Pjeturss there is no
escape from the conclusion that an enormous erosion was carried out
in Quaternary times, and this seems to be in accordance with the
view of some Norwegian geologists that the Norwegian fjords are
of Quaternary, even Middle or Late Quaternary age. Pjeturss’ main
arguments, obtained in Snæfellsnes, are, it must be admitted, very
strong and seemingly also those derived from the moraines at Hval-
fjörður, where a striated floor of the moraines is also reported. —
I have in the foregoing pointed out some difficulties which arise
in connexion with Pjeturss’ system, but they all seem to be of no